Rock drill



March 8, 1932. G. HA GILMAN ROCK DRILL Filed Sept 23, 1926 um. Q/

i UNITED.STATES.

GEORGE` "n: GILMA'N, fon BELMONT; Massaonusii'ivrs,ffission-oit,i BY. MESNIL Assistita: i

MENTS, :To WORTHINGTON PUMP AND "Appncaan mea septeiiuiefes, 192e:- seal No. 137,261.

c My inventionirelates-.to krock drills, particularly butnot exclusively Yto those'f of the fluid light ofv the accompanying `drawings of' an example of the invention', while the scope of .Y

the inventionwillr be more' particularly pointed. out in the appended claims.; o

yIn-the drawings y c Fig. 1 is an axial longitudinal `section of a rock drill embodying the invention; and o Figs. l2 andY 3 respectively are sections on 1. the lines 2 2 and 3 3 of Fig. 1, Fig..2 showi. p Y

` parting the momentum ofthe head 1 and:

ing the pistonina different positio ,c

Referring-to the drawings I have shown a casing in. which reciprocates .a hammerv piston havingia vcylindrical head 1,the cylin` drical rearward extension 3,andxthe cylin. drical hammer bar; 5,y the rearwardextension; adjacent its juncturewith the piston being,

and as it forms no part of my present invenofreduced cross-section as shown at'7.

, The casing ,contains a Vpiston chamber hav- Ving the large bore 9 and a smaller rearward bore V.11 the .wallsof which have a fluid tight fit with the head1 `and-.rearward extension 3V of the piStOnreSpectiVely, while therhammer4 bar extends "through anflopening 13. in. theY front .wall offthis chamber, .fitting the opening in a substantially iiuid tight manner, Vtheparts as shown being so proportioned-that inzall positions ofthepiston the hammer baris received bythe Opening .13.V

As illustrated, forwardlyy t of sleeve 17.` HereinY the sleeve 17 at its forward end is provided. with anenlarged bore 19 into which points receive and prevent rotation' of the drill steel relative tothe chuck. y,

Itfwill be understood. that when the ma,- chine is in operation, for each blow of the `hammer thefshankA Ofthedrill ksteelk recip- V vthe fopening. 13 the casingis provided witha chuck chamf, ber 15 in which is 'rotatably `mounted afchuckA lsage and A,radial lpassages.

rocates relativeto the `chuck with great resulting wear on the bore yof the bushing Z`21 receivingxthe drill shank.. Consequentlyy by ythe' present'con'struction of shankfand bore 23,` when one setfof star points receivingthe drillfsteel is worn the other set maybe .uti-; lized `for 'non-.rotatably securing the shank/co thechuck. i o

As show-n the drill Vsteel'isprovided with: acollar131 which normally rests againstthev front endof .the bushing so as to determine the ypositionof the end of theshankrelative to the end ofthe hammer kbarwhenthe blow. is struck, andfit will-beV observed .that herein` theV hammer bar constitutesy means 4for imtionit will not bek described with any. more particularity than necessary to understand the presentV invention.V

,c As illustrated, rotatably moim1ed'-inVK theA Y l y rMno'HrNniet( coRPoRArroN, or NEW YORK, 1

1 N, Y.'A CORPORATION OFVIRGINIAQL y I casing .is a valve33`havingabore 35 in communication` withj a' motive fluid supply hose v (not shown) the valve being provided witha port 371for placingy the bore35 of the valve kin communication Y with vthe intakey passage v39. v

for the hammer. In communication kWiththe passagek 39L`is anfannular ,passage 41 placed incommunication with kthe small bore 11 of the piston chamber bya pair Oforadial lpas;v sages I43 and by slots 15, which'latter com;-

municate laterally withfsaid annular pas# v y p y Extending through Vthecasing parallel tothe bore 11 arey passages 47 lin communication at oneoftheir ends with theslots 45and at their other ends. with the enlargement@ of the bore A11. `As

shown by Fig. 2 the casing is provided withk passages 51 which'at their rearward f ends"y through ports into the forwardr'portion of.. the bore 9, the ports 53 being in approximatelythe same plane asthe slots 45 so that when',

.951sl open 'through ports 53 into the forward por-f V tion ofthe bore 11, and at their other ends the piston is in the position shown by Fig. 1 motlve fluid supplied the bore 11 passes through the passages 51 and is effective to cause the return stroke of the hammer against the `pressure of the motive fluid continuously exerted against the rear end of the rearward extension 370i the piston. When the parts are inthe position shown byFig.2thercduced herein is providedwith an exhaust conduit 57 in communication with the atmosphere and `com'municatingwith the bore 9 through a porty59. As will be understood by those skilled in the art the head 1 ofthe piston controls the port 59 so as to exhaust the front end of the bore 9 on the latter part of the rearward stroke and therear end of said borcon the latter part of the forward stroke.

Asillustrated, the drill steel is provided with an axial bore 61,y which bore, as will be understood by those' skilled in the art, eX- tends throughout the entire length of the steel.l The bore receives the front end of a water tube 63, which may be utilized for injecting cleansing fluid, such as water underV pressure, into the bore 61l for washing the cuttings from the drill hole in the rock. As shown the water tube 63 extends rearwardly through thepiston andpiston chamber, and at its rear end is received in a plug 65 forme ing part of a water connection 67. LHerein the water connection carries the swivelled tube 69 for attachment to a hose 71 conducting water under pressure to the machine from aV suitable source of supply.v

As illustrated, the plug 65 1s received in ay bore 73 opening on the rear'end ofy the back head of the casing, thei'plug being retained in 'said bore by' means of a oke member or bar 75 which engages the bac end of the plug and is secured to and drawn toward the casing'by means of screw bolts 7 7.A As shown the' plug 65 is provided' with a bore 79 which receives a packing 81 of rubber or 'other suitable material compressed about the end of the tube by means of a plug 83 screw threaded into the end of the bore 79. At the y bottom of the bore 79 the water connection is provided with arpassage 85 receiving the extreme rearward end of the tube, the passu e 85 having in communication therewith a ateral passage 87 in communication with the interior of the swivelled member 69.

In the present embodiment of my invention the bore-89 of the piston, through whichy the water tube 63 passes, is of greater diame# ter than the exterior diameter of the tube, so as to maintain said bore in Huid conducting relation with the portion of the chuck chamf lof the water tube. AAs shown the plug 83 has a `frusto-conical end surface 97 which fits a corresponding frustoconical bottom of the bore 73 so as to render the joint between the back head Vof thefcasingv and plug' fluid tight. Leading from the bore 95 through'the plug to the exterior thereof areradial rpassages 99, while leading from the bore 73 to the 'atmosphere Aforwardly of thev plug 65 is a'radial-passage 101.

It will be observed that by the above described construction leakage of air to the chuck chamber by way of the bore of the pis-y ton receivingy the water tube is prevented, and that the chuck chamber is vented to the atmosphere by way of such bore. f

Asfillustrated, the opening 13 which receives the hammer bar is enlarged intermediate its length yto form an annular groove 103 placed in communication with the atmosphere by a passage 105 so as to vent motive fiuid which may leakfromthe forward end of the bore 9 toward the chuck chamber. As illustrated,-the removable bushing 21 received in the bore 19 of the chuck sleeve 17 is provided on its exterior with longitudinally extending grooves 107 which open into the s ace in the chuck chamber about the end ofy t e shankV ofkk the drill steel and communicate at theiriforward ends with the atmosphere. These passages in the normal operation of the machine will serve to drain Water fromthechuck, which may find its way from the chuckintothe bore of the drill steel.-

, They mechanismV for rotating the chuck illustrated herein is of the same general con-` struction as that described in United States Patent 1,605,715 hereinbefore referred to. At the rear'of the machine is a motor indicated at 109 which drives a pair of shafts 111, the latter being mounted in bearings 113and operating reduction gearing mechanism 115 for rotating the chuck. As shown the shafts 111` are each provided with a bore 117 which is closedv at its front end and which communicates through its rear end with passages 119'opening in the lubricant lreservoirs 121'y in the handle members 123 carried by the back head of the casing. Communicating with the bores 109 are radial passages 125 for conductingthe lubricant from the bores to the various bearings associated with the shafts. As shown the reservoirs 121 arey placed in communication bysmeans of the communicating passages 127-129, one or the lreservoirs being provided. with ay screw threaded lubricant opening 131 normally sure grease gun or the like.

Although I have describedior purposes of illustration'a speciiic example ot my inven-y tion it is to be understood that` Yl am not limited thereto, andl that withinthe scope of my invention wide deviations may be made f ends of said chamberior'actuation of said` without departing from the spirit of my inf vention. i v x Claims:

1. A rock drillhaving, inV combination, a Y

casing, a piston a fluid conducting tube yextending into said casing coaxially of said piston, a mounting for said tube comprising a part rotatably received by a rearwardly opening bore in-said casing,a radially extending water hoseconnection rigidly carried by e 'said part, a detachable yoke-like member for securing said part infsaid'rbore, said part and yoke being formed with cooperating portions for ositivel securing said aart in diii'erent P Y e l predetermined rotative positions relative to said casing. Y s s 2. A rock drill having, in combination, a

casing, a piston, coaxiallyarranged tubes extending into said casing coaxially of said,

piston, said casing having a rearwardly opening bore, a plug received by said bore, said plug having afforwardly opening concavity orreceiving the rear end of the inner Jtube of said coaxiallyy arranged tubes, a resilient packing4 in said concavity, the outer tube of said coaxially arranged tubes being formed l integrally with a head screw-threaded `into said concavity for compressing said packing about said inner tube, andmeans for removably securing said plug in said bore. Y

3. A rock drill having, in combination, a

casing, a hammer piston, a cylinder chambery for said piston formed in saidcasing,'means for admit-ting compressed air to opposite ends or' said chamber for-actuation of said piston, Vsaid casing having a chuck chamber containing va rotary chuck for a hollowdrill f steel, independent motor means `for rotating said chuckrelativel to said casing, said piston having an axial passage opening on opposite ends thereof, a water tube for saidV drill steel carried at its rear end by the rear end of said casing and extending through said piston into said chuck chamber; and means for preventing leakage of air `from said cylinder chamber to said hollow drill steel comprising a Vforward yreduced diameter extension on said piston, which extension isfreely rotatable relative to said chuck and in all positions osaid ,piston Vcloses'communication between said cylinder` chamber and said chuck chamber, and a tube for venting said chuck` chamber carried bysaid Vrear end of saidcasf ingfaiiddittingfthe rear end of said axialfpas# sage fin aluid tight manner, saidtube sure:k

torfadmitting compressed air Vto :opposite piston,. saidcasing having a chuckchamber containing a chuck `for a hollow drill steel, said piston having an axial passage opening on opposite `ends'thereoi", water tube for said drill steel carried at its rear endfby the rear end'lof. said casing "and extending through saidpistoninto said chuck chamber and means forfprevent-ing leakage o-air from saidfcylinder chamber yto 'said'hollow drill,V steel comprising a forward reduced diameterk extension onsaid piston, which extensionin allpositions of said piston closes communica-` tion between said cylinder chamber and Vsaid lchuck chambernand a tube for venting said chuck chamber carried by said rear Vend of; said casing and iitting' the rear end of said axialpassage in .a fluid tight manner, said` tube-:surrounding said water tube inaspaced relation tothe exterior .of the latter, said cas i ingalso formed withanannular groove rvented to the atmosphere, which groove surrounds said forward extension of said piston in con-r` tacting relation therewith.

5. A rock drill having in combination, a casing, a. hammer piston, a cylinder chamber for said piston formed in'said casing, means for yadmitting compressed air to opposite ends of said Vchamber for actuation of said pistomsaid casing having a chuck chamber containing a rotary chuck for a hollow drill steel, independent motor means for rotating j said chuck relative to said casing, said piston havingan axial passage openingonopposite ends thereof, a water tubefor said drill steel carried at its rear end by the rear end of said casing and extending through said piston into said chuck chamber; and mea-ns for pre-v venting leakage of air from said Lcylinder chamber to said hollow drill steel compris-V ing a forward reduced diameter extension on ,said` piston, which extension is freely rotat-k able relative to said chuck and in all positions of said piston closes communication between said'cylinder chamber and said chuck chamber,-a rearward reduced diameter extension s on said piston extending from said cylinder chamber, and atube for venting said chuck chamber carried by said rear endl of said casing and fitting in a fluid tight manner thatfportlion of saidaxial passage which is in Vsaid rearward extension, said casing also l e 1,348,3arv

formed with anr annular groove'vented tothe atmosphere, which groove surrounds said forl Ward extension of said piston in contacting relation` therewith. f 6. A rock drill having, in combination, a

casing, a hammer piston,V a cylinder chamber for said piston formed in said casing, means for admitting compressed air to opposite ends of said chamber for actuation of said piston, w said casing having a chuck chamber containing 'a chuck for a hollow drill steeel,ysaid piston having an axialv passage opening on opposite ends thereof, a water tube for said drill steel carried at its rear end by the rear w end yof said casing and extending through said kpiston into said chuck chamber; and means for preventing leakage of air from said cylinder chamber to said hollow drill steel comprising a forward reduced diameter extension on said piston, which extension in all positions of said piston closes communication between said cylinderichamber and said chuck chamber, a rearward reduced diameter extension on said piston ex'- 254 tending from said cylinder chamber, and a tube for venting said chuck chamber carried by said rear end ofsaid casing and fitting in a fluid tight manner that portion of said axial passage which is in said rearward extension, said casing also formed with an annular groove vented to the atmosphere, which groove surrounds said forward extension of e said piston in contactin relation therewith.y

In testimony whereo I have signed my name to this specification.

GEO. H; GILMAN. 

